Process of forming porous pots for voltaic batteries



(No Model.)

0. R. GOODWIN. V PROCESS OF FORMING POROUS POTS FOR VOLTAIG BATTERIES. No. 431,968.

Patented July' 8, 1890.

m: NORRXB PRTERS co, mum-um); WASHINGTON, u, c.

UNITE STATES OIIARLES RHODES GOODVVIN, OF PARIS, FRANCE, ASSIGNOR TO THE ELEC- PATENT OFFICE TRIO GAS LIGHTING- COMPANY, OF MAINE.

PROCESS OF FORMING POROUS; POTS FOR VOLTAIC BATTERIES.

SPECIFICATION forming part of Letters Patent No. 431,968, dated July 8, 1890.

Application filed May 28,1886. Serial No. 203,503. (No model.) Patented in France September 9, 1885, No. 171,105 in Belgium February 20, 1886,11'0. 72,073, and in England February 25,1886,N0.2,7'73- To all whom it may concern.-

Be it known that 1, CHARLES Rnonns Goon- WIN, of the city of Paris, France, have invented new and useful Improvements in the Process of Forming Porous Carbon Pots for Voltaic Batteries, of which the following is a full, clear, and exact description, and for which I have obtained Letters Patent in France September 9,1885,No. 171,105; in Belgium February 20, 1886, No. 72,073, and in Great Britain February 25, 1886, No. 2,773.

This invention relates to improvements in the porous pots employed in voltaic batteries for separating the exciting-liquid from the depolarizing agent; and it consists, first, in forming the pots of a highly-porous carbon, and, secondly, in the method of increasing the area of the porous surface of these vessels.

Attempts have already been made to make porous pots of carbon with, however, but in different results, owing to their insufficient porosity.

In order to impart to the carbon the necessary degree of porosity for this special application, I proceed as follows: I mix with finelydivided hard carbon-gas-carbon, for examplethc residuum from the distillation of gas and analogous products from coal orits equivalents for this special purpose-such as prepared charcoal, lignite, and the like, sawdust, chopped straw, or similarly constituted organic material of a particulate or fibrous and carbonaceous nature, capable of acting as spacing substances and of leaving pores or spaeesin the mass when baked in the proportions of from ten to forty per cent. of the sawdust or said similar material. The mixing or agglomerating should be very carefully and thoroughly accomplished and the mass rendered plastic by any suitable agglomerant such, for example, as molasses, or sugar candy, or dextrine. I have used a mixture of sawdust, rice powder, and dextrine together with good results. The mixture is then molded under sufficient pressure to form and retain the vase into the desired shape and then subjected to a firing process, in which the heat must not be so high nor must the pressure have been so great as to destroy the fibrous or particulate structure of the sawdust or said similar spacing material, as this would destroy the spaces or artificial pores which give to the carbon the degree of porosity sought. I

find from 800 to 1,500 centigrade a proper temperature. Carbon thus prepared is of such a porous nature as torender its employment very advantageous both as a porous pot and electrode at the same time.

The pots may be made of any form; but it is, however, preferred, in order to increase the area of their porous surface, to adopt the arrangements described by way of example, with reference to the accompanying drawings, wherein- Figure 1 represents a vertical section of a cylindrical porous pot; Fig. 2, an elevation, and Fig. 3 a plan, of a fluted pot. Fig. 4 shows an elevation, and Fig.5 a horizontal section, of a ribbed pot. Fig. 6 is a section of a modified form of ribbed pot. Fig. 7 shows a vertical section, and Fig. 8 a horizontal section, of a pot having ribs fitted on. Fig. 9 shows a top view of one of the holders for the ribs.

In Fig. 1 the pot'a consists of a cylinder closed at bottom by a plug 1) of wax or other material. Itis provided with a cover 0, which is furnished with a metallic contact-piece d for the attachment of the conducting-wire, preferably embedded in the carbon before or after firing. The cover is provided with perforations e and is luted or otherwise fixed to the vessel a. A porous pot of this kind gives excellent results, owing to the porosity of the carbon of which it is composed; but the efiect may be still further increased by employing the arrangements illustrated in Figs. 2 to 9, whereby a larger contact-surface for the liquid is obtain. ble.

Figs. 2 and 8 show a grooved or fluted pot, the grooves or flutes serving to receive the zincs or negative elements I). The zines b may be insulated from the pot by india-rubber or other insulating material 0, held in place by similar bands d.

Figs. 4 and 5 show a pot at, having a larger number of ribs with sharp edges. Fig. 0 represents a section of a pot whose porous area is augmented by inserting fiat carbon strips 1) in the flutes or grooves, extending the whole height of the pot. These wings or strips may be either cemented to the pot a before firing or they may be simply held in place by indiarubber bands.

In Figs. 7, 8, and 9 the pot is composed of a cylindrical vessel a, to which is fixed either by compression or by being cemented together by heat at top and bottom two flanges I), having notches 0, (see Fig. 9,) in which are inserted fiat carbons d, the carbons being thus held atboth of their extremities. The cover e is also provided with a central perforated tube f, which allows of the liquid in the battery rising up the center and entering the porous pot, whereby the capacity of the battery is still further increased. This tube is equally applicable to all the arrangements of porous pots herein referred to. The depolarizing agent is contained in the annular space 9, which is closed at bottom by a plug it of impervious material. The number and dimensions of carbons d and grooves 0 may be varied and they may project from said grooves to any extent desired.

These improved porous pots may be used in any kind of battery, are especially advantageous in batteries of the Leclanch type in which case the peroxide of manganese would be placed in the pot, which is itself disposed in a second vessel containing the excitingliqnid (solution of sal-ammoniac) and the negative element, (zinc) I claim- 1. The process of manufacturing carbon pots of increased and suflicient porosity to serve as both vases and electrodes for voltaic batteries, which consists in first mixing by any proper agglomerant with finely-divided gas or other hard carbon such organic spacing substance as is capable of being so carbonized by heat as to leave the mixture interpenetrated with its porous residuum and open and porous in texture, then forming the same with only sufficient pressure to attain the desired form, and then firing the same, so as to carbonize without destroying said spacing substance.

2. The process of manufacturing highly-porous pots for voltaic batteries by mixing by any proper agglomerant finely-divided gas or other hard carbon with particulate organic matter capable of such carbonization as not to sensibly diminish the volume of the particles forming the paste with suitable pressure, and firing so as to convert said organic matter into charcoal within the pores or spaces of the mass.

3. In the process of forming a highly-porous carbon pot, first mixing hard carbon with an organic substance capable of retaining substantially its normal space afterit is carbonized, uniting the above ingredients by means of a suitable agglomerant, and subsequently firing the mixture sufficiently to carbonize the organic matter without destroying the structure.

The foregoing specification of my improvements in porous carbon pots for voltaic batteries signed by me this 11th day of May, 1886.

CHARLES RHODES GOODWIN.

\Vitnesses:

Row. M. HOOPER, ALBERT MoREAU. 

